7up recently changed their 16.9 bottles. The shape changed a bit and the bottle is a bit more sturdy. It's great. They used to jam every now and then and stacking more than about 10-12 got dicey. Now I'll go 16 high or so with no problem
I like cans for the profit margin, but bottles can bring you more overall profit. If a person is going to buy one drink a day and they buy a can vs. a bottle then you make less on that person.
Absolutely choose a machine that can do it all, if you can. Variety is key. Those machines can vend about anything. I have 10 oz orange juice, 16.9 oz water, Monster, 20 oz gatorade, coke can, 24 oz Mountain Dew, 16.9 oz green tea, 16.9 oz 7up among others all in one location. Whole lot better than just the usual. They ask for it - they get it.
Agreed - if they have always had cans, they won't adjust too quickly to a bottle for twice the price. But, if you can use a bottle machine. Then use a couple selections to introduce a bottle. Especially in the summer, maybe try a gatorade. Grocery stores usually always have 8 packs for $5 (20oz). That's 62 cents per. You'll easily get $1.25 out of that bottle. See how it goes.